SystemUI: Make the HSPA+ drawables more consistent with the HSPA drawables

Though the older HSPA+ drawables are sharper, that makes them look
out of place in comparison with the HSPA drawables.

Change-Id: I76313ae0125b3a8fda928b240f33715e48f77867
SystemUI: highlight quick settings and notification clear buttons
Actually make use of the drawables bestowed upon us by the Google